The present invention relates to a method for producing an automobile column by hot-forming and press hardening.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
The requirements profile for vehicle safety increases in the automotive industry due to regulatory and manufacturer-specific guidelines. At the same time, the automobile manufacturers strive to reduce the weight of the automobile bodies in order to minimize fuel consumption and CO2 emission. This creates a divergence between low weight and high bending and torsion strength and high crash safety.
According to one approach, for example light-metal materials, in particular aluminum alloys, or bodies in hybrid construction, for example made of metallic alloys and fiber composite material or plastics, can be used. However, the aforementioned approaches are both associated with high material costs, which in turn increases the vehicle production costs of models produced in large quantities.
However, a metallic alloy, in particular steel, still remains the preferred material for constructing the body, in particular the raw body. Due to consequent improvements, steel is still viewed as a high-tech material which due to different processing approaches represents a good compromise between favorable manufacturability, excellent crash safety and long service life.
Heat-treatment is according to the state-of-the-art typically performed in a temperature range between 320° C. and 400° C. and hardly changes the material properties and the strength values adjusted in the hot-forming and trans-hardening process. At the same time, however, the ductility of the material is increased so as to allow superior fold formation in a crash.
However, the additional heat-posttreatment once more increases the production costs due to significantly higher tooling costs up to the start of the series production.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved automobile component and a method for its manufacture, which has lower manufacturing costs compared to the state-of-the-art, while simultaneously allowing precise adjustment of material properties inside the component.